HUALIEN, Taiwan－Rescuers braved aftershocks on Thursday that were coursing through a dangerously leaning apartment block that was partially toppled by a deadly earthquake a day earlier.

At least 10 people were killed when a 6.5 magnitude quake struck the popular tourist county of Hualien, which has a population of about 100,000, on Tuesday, the Associated Press reported. More than 260 were left injured, according to the local fire agency, which slashed the number of missing to 10.

Among the dead were four tourists from the mainland. Three, all female, were found in the damaged Yun Men Tusi Ti apartment block, which emergency responders have focused on since the quake.

The three were believed to be staying at the Beauty Stay Hotel, which was on the second floor of the apartment block.

Another female tourist, Yu Fei from Xiamen, Fujian province, was rescued from the apartment block on Wednesday, but died that evening.

A local TV station ran an interview with a man who said he was Yu's husband. Yu, 39, was traveling with the couple's young son on the island. The son survived the quake with light injuries.

"They were traveling on their own, as I was busy and couldn't accompany them," said the man, who had rushed from Xiamen to Hualien. "I got in touch with my son－he cried."

The remaining 10 missing people also were believed to be in the apartment building. Five are believed to be mainland tourists, four adults and one child. So far, no signs of life have been detected in the building, local rescue authorities said.

The Taiwan Affairs Office of the State Council said authorities on the mainland would keep close contact with those in Hualien and help families of the dead get to Taiwan.

The Red Cross Society of China has provided 1 million yuan ($158,270) for rescue operations, saying it was ready to send rescue teams as well.

Other mainland authorities, such as the Association for Relations Across the Taiwan Straits, Fujian province and the Guangxi Zhuang autonomous region, said they would each donate 1 million yuan to Hualien.

The earthquake, the most severe to hit Hualien in five decades, jolted waters near Hualien at 11:50 pm on Tuesday.

The powerful tremor left a handful of buildings badly damaged, with some, such as the apartment block, leaning at precarious angles. Some roads were torn up and hundreds of people were forced into shelters at local schools and a stadium.

The lower floors of the 12-story Yun Men Tusi Ti apartment building pancaked, leaving the structure leaning at a 50-degree angle and sparking fears of imminent collapse.

Despite those risks, rescuers repeatedly returned to the building to search for survivors. Strong aftershocks continued to strike, sending the teams scurrying out, only to return soon after the aftershocks to resume their grim task.

A Red Cross worker at the scene estimated that the building had tilted another 5 percent overnight, adding he had little hope of survivors being found on its lowest floors.